"They were met at the airport by Ariana's boyfriend, Mac Miller," a source tells E! News. "When Ariana got off the plane, Mac greeted her on the tarmac with a long hug followed by a kiss. Mac also gave Ariana's mom a hug. It was a very emotional reunion and they stood talking for a minute before getting into the car. Ariana looked exhausted and like she didn't get much sleep. She seemed like she just wanted to get home and be with her loved ones."

Her official team shared a lengthy message via Twitter, sending support to the victims' loved ones. It read, "Tonight, our hearts are broken. Words cannot express our sorrow for the victims and families harmed in this senseless attack. We mourn the lives of children and loved ones taken by this cowardly act. We are thankful for the selfless service tonight of Manchester's first responders who rushed towards danger to help save lives. We ask all of you to hold the victims, their families and all those affected in your hearts and prayers."

At least 22 people, including children, were killed in the attack and more that 50 others suffered injuries, authorities said. U.K. authorities suspect a suicide bomber is responsible, NBC News reported. The bombing occurred as concertgoers were departing from the venue.

"This is currently being treated as a terrorist attack until police know otherwise," Greater Manchester police said.

Shortly after news broke that fans were evacuated from Manchester Arena, Grande's rep shared with E! News that the "Break Free" singer was "okay" and her team was "further investigating what happened."

Grande has been scheduled to continue her Dangerous Woman World Tour on Thursday and Friday with a stop at London's O2 Arena. It wasn't clear if the performance was still on.

"Along with everyone else, we are shocked and saddened by the terrible tragedy in Manchester. Our thoughts are with all those affected," the venue said on Twitter. "Ariana is due to perform at The O2 on Thursday and Friday and we will advise as soon as we can as to the status of those shows."